Re: pg_ctl stop -m immediate on the primary server inflates sequences

Bernd Helmle írta:
>
>
> --On 10. April 2010 09:26:41 +0200 Boszormenyi Zoltan <zb@cybertec.at>
> wrote:
>
>> The above is quite reproducable, "pg_ctl stop -m immediate"
>> "usually" inflated my serial sequence, but I had two occasions
>> when not. The 69 -> 70 was one. The inflated increase is always 33:
>
> AFAIKS sequences are pre-logged with 32 values to WAL to avoid
> overhead. I suspect this is why you are seeing those gaps.

Then it should happen all the time, even with "-m fast" or "-m smart", no?

It seemed like my sequences have a CACHE 32 setting, which would
apply to every client that connects, runs nextval() once and disconnects.

But it didn't happen all the time, so it's not deterministic.

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Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
http://www.postgresql.at/